For years, ocean scientists have dreamt about sending small fleets of underwater robots to explore the ocean depths. But the ocean presents formidable obstacles to navigating and communicating with robots in the deep. On New Year’s Eve, an expedition gets under way to try cutting-edge technology to overcome those barriers. If successful, the research cruise could herald a revolution in the way scientists explore the deep sea. On an 18-day expedition to the South Atlantic Ocean aboard the research vessel Knorr, researchers will try something they’ve never done before. They will unleash two deep-sea robots, called Puma and Jaguar, at the same time. The two are Autonomous Underwater Vehicles (AUVs), which means they swim freely—unpiloted and unattached via a cable to the ship. As the underwater “cats” roam miles below, scientists and engineers will test navigation and communication technologies that will enable the AUVs to “talk” to each other and to scientists aboard Knorr in real time. The robotic dynamic duo will prowl a little-explored stretch of the Mid-Atlantic Ridge, the volcanic mountain chain that winds like a zipper through the middle of the world’s oceans. They will search for hydrothermal vents, which emit chemical-rich fluids that sustain unusual communities of deep-sea life. Equipped with sonar to map the seafloor and chemical sensors to detect vent fluids, Puma’s main job will be to survey large areas to help scientists find possible vent sites. Jaguar will be hovering by, ready to fly in close and take images of vents and vent life.